本文实例讲述了PHP基于ffmpeg实现转换视频，截图及生成缩略图的方法。分享给大家供大家参考，具体如下：
resizeimage("1.jpg",30,"small1.jpg");
class ImageResize {
//图片类型
var $type;
//实际宽度
var $width;
//实际高度
var $height;
//改变后的宽度
var $resize_width;
//改变后的高度
var $resize_height;
//是否裁图
var $cut;
//源图象
var $srcimg;
//目标图象地址
var $dstimg;
//临时创建的图象
var $im;
function resizeimage($img,$wid,$hei,$c,$dstpath) {
$this->srcimg = $img;
$this->resize_width = $wid;
$this->resize_height = $hei;
$this->cut = $c;
//图片的类型
$this->type = strtolower(substr(strrchr($this->srcimg,"."),1));
//初始化图象
$this->initi_img();
//目标图象地址
$this -> dst_img($dstpath);
//--
$this->width = imagesx($this->im);
$this->height = imagesy($this->im);
//生成图象
$this->newimg();
ImageDestroy ($this->im);
}
function newimg() {
//改变后的图象的比例
$resize_ratio = ($this->resize_width)/($this->resize_height);
//实际图象的比例
$ratio = ($this->width)/($this->height);
if(($this->cut)=="1") {
//裁图 高度优先
if($ratio>=$resize_ratio){
$newimg = imagecreatetruecolor($this->resize_width,$this->resize_height);
imagecopyresampled($newimg,$this->im,$this->resize_width,$this->resize_height,(($this->height)*$resize_ratio),$this->height);
ImageJpeg ($newimg,$this->dstimg);
}
//裁图 宽度优先
if($ratio<$resize_ratio) {
$newimg = imagecreatetruecolor($this->resize_width,$this->width,(($this->width)/$resize_ratio));
ImageJpeg ($newimg,$this->dstimg);
}
} else {
//不裁图
if($ratio>=$resize_ratio) {
$newimg = imagecreatetruecolor($this->resize_width,($this->resize_width)/$ratio);
imagecopyresampled($newimg,($this->resize_width)/$ratio,$this->dstimg);
}
if($ratio<$resize_ratio) {
$newimg = imagecreatetruecolor(($this->resize_height)*$ratio,($this->resize_height)*$ratio,$this->dstimg);
}
}
}
//初始化图象
function initi_img() {
if($this->type=="jpg") {
$this->im = imagecreatefromjpeg($this->srcimg);
}
if($this->type=="gif") {
$this->im = imagecreatefromgif($this->srcimg);
}
if($this->type=="png") {
$this->im = imagecreatefrompng($this->srcimg);
}
if($this->type=="bmp") {
$this->im = $this->imagecreatefrombmp($this->srcimg);
}
}
//图象目标地址
function dst_img($dstpath) {
$full_length = strlen($this->srcimg);
$type_length = strlen($this->type);
$name_length = $full_length-$type_length;
$name = substr($this->srcimg,$name_length-1);
$this->dstimg = $dstpath;
//echo $this->dstimg;
}
function ConvertBMP2GD($src,$dest = false) {
if(!($src_f = fopen($src,"rb"))) {
return false;
}
if(!($dest_f = fopen($dest,"wb"))) {
return false;
}
$header = unpack("vtype/Vsize/v2reserved/Voffset",fread($src_f,14));
$info = unpack("Vsize/Vwidth/Vheight/vplanes/vbits/Vcompression/Vimagesize/Vxres/Vyres/Vncolor/Vimportant",40));
extract($info);
extract($header);
if($type != 0x4D42) { // signature "BM"
return false;
}
$palette_size = $offset - 54;
$ncolor = $palette_size / 4;
$gd_header = "";
// true-color vs. palette
$gd_header .= ($palette_size == 0) ? "\xFF\xFE" : "\xFF\xFF";
$gd_header .= pack("n2",$width,$height);
$gd_header .= ($palette_size == 0) ? "\x01" : "\x00";
if($palette_size) {
$gd_header .= pack("n",$ncolor);
}
// no transparency
$gd_header .= "\xFF\xFF\xFF\xFF";
fwrite($dest_f,$gd_header);
if($palette_size) {
$palette = fread($src_f,$palette_size);
$gd_palette = "";
$j = 0;
while($j < $palette_size) {
$b = $palette{$j++};
$g = $palette{$j++};
$r = $palette{$j++};
$a = $palette{$j++};
$gd_palette .= "$r$g$b$a";
}
$gd_palette .= str_repeat("\x00\x00\x00\x00",256 - $ncolor);
fwrite($dest_f,$gd_palette);
}
$scan_line_size = (($bits * $width) + 7) >> 3;
$scan_line_align = ($scan_line_size & 0x03) ? 4 - ($scan_line_size &
0x03) : 0;
for($i = 0,$l = $height - 1; $i < $height; $i++,$l--) {
// BMP stores scan lines starting from bottom
fseek($src_f,$offset + (($scan_line_size + $scan_line_align) * $l));
$scan_line = fread($src_f,$scan_line_size);
if($bits == 24) {
$gd_scan_line = "";
$j = 0;
while($j < $scan_line_size) {
$b = $scan_line{$j++};
$g = $scan_line{$j++};
$r = $scan_line{$j++};
$gd_scan_line .= "\x00$r$g$b";
}
}
else if($bits == 8) {
$gd_scan_line = $scan_line;
}
else if($bits == 4) {
$gd_scan_line = "";
$j = 0;
while($j < $scan_line_size) {
$byte = ord($scan_line{$j++});
$p1 = chr($byte >> 4);
$p2 = chr($byte & 0x0F);
$gd_scan_line .= "$p1$p2";
}
$gd_scan_line = substr($gd_scan_line,$width);
}
else if($bits == 1) {
$gd_scan_line = "";
$j = 0;
while($j < $scan_line_size) {
$byte = ord($scan_line{$j++});
$p1 = chr((int) (($byte & 0x80) != 0));
$p2 = chr((int) (($byte & 0x40) != 0));
$p3 = chr((int) (($byte & 0x20) != 0));
$p4 = chr((int) (($byte & 0x10) != 0));
$p5 = chr((int) (($byte & 0x08) != 0));
$p6 = chr((int) (($byte & 0x04) != 0));
$p7 = chr((int) (($byte & 0x02) != 0));
$p8 = chr((int) (($byte & 0x01) != 0));
$gd_scan_line .= "$p1$p2$p3$p4$p5$p6$p7$p8";
}
$gd_scan_line = substr($gd_scan_line,$width);
}
fwrite($dest_f,$gd_scan_line);
}
fclose($src_f);
fclose($dest_f);
return true;
}
function imagecreatefrombmp($filename) {
$tmp_name = tempnam("/tmp","GD");
if($this->ConvertBMP2GD($filename,$tmp_name)) {
$img = imagecreatefromgd($tmp_name);
unlink($tmp_name);
return $img;
}
return false;
}
}
附：
完整实例代码点击此处本站下载。更多关于PHP相关内容感兴趣的读者可查看本站专题：《》、《》、《》、《》及《PHP数学运算技巧总结》
希望本文所述对大家PHP程序设计有所帮助。
